D&D 5E (2014) Best way to balance an encounter against a level 10 5 player party?

[Jaiken]

Hello I was wondering if this group of enemies would suffice against my players.

Enemies:
1) 1 Mind Flayer
2) 2 Grells
3) 1 Champion
4) 1 5th level spellcaster

Players
1) Half Orc Vengeance Paladin
2) Hill Dwarf Land Druid
3) Variant Human (great weapon master) Storm Herald Barbarian
4) Pompup (custom race that has the resistances of Fae and can deal 1 extra damage per long rest whether it is magic or melee) Lore Bard
5) Reborn Dragonborn Magus (custom class that mixes Fighter and Wizard together minus the spell book and has 1d8 hit points, has the same spell progression of a typical Wizard but half the spell slots).

Battlefield:

30ft x 40ft circular room.

Battle Plan:

My plan is to have the Champion stand in the middle of the room to distract and protect the mage and Mind Flayer.
Mind Flayer will be positioned at the 9 0 clock position using mind blast as the Mage prepares to counterspell the Bard and Druid.
The grells will hang on the ceiling and Mae their way to grapple the Druid and Bard.

Any adjustments I need to make to ensure this encounter is fair but difficult without being cheap?

 

[aco175]

Is this the only fight of the day, or has the PCs battles some other things and are down on resources?

Seems like the 5th level spellcaster should be a 15th level. The CR7 mind flayer does have a DC15 INT save blast that could hurt some. I would have 3 of them and skip the other caster. Grells are nothing much so it depends on the champion. Likely need 3 of them as well.

 

[Jaiken]

Is this the only fight of the day, or has the PCs battles some other things and are down on resources?

Seems like the 5th level spellcaster should be a 15th level. The CR7 mind flayer does have a DC15 INT save blast that could hurt some. I would have 3 of them and skip the other caster. Grells are nothing much so it depends on the champion. Likely need 3 of them as well.

The only other fight are the three Goblins that man the tower with ballista cannons that the players enter to encounter the Mind Flayer and its group.

Why should the 5th level spellcaster be 15th level? Unless it is an Archmage? Having summon construct and counterspell should be useful right?

 

[aco175]

Why should the 5th level spellcaster be 15th level? Unless it is an Archmage? Having summon construct and counterspell should be useful right?

A party of 10th level PCs is way more powerful than it look. A 5th level caster going against them will die in the first round and not do much if he gets to go in the first place. A 5th level caster is a CR1 or maybe 2 monster with a fireball it might do something. Counterspell might do something or it might just get killed by a shapeshifted druid since it has so few HP.

 

[Jaiken]

A party of 10th level PCs is way more powerful than it look. A 5th level caster going against them will die in the first round and not do much if he gets to go in the first place. A 5th level caster is a CR1 or maybe 2 monster with a fireball it might do something. Counterspell might do something or it might just get killed by a shapeshifted druid since it has so few HP.

Understood. I will use an Archmage then.

 

[Distracted DM]

In my experience, they'd wipe the floor with this encounter... But I have very optimized and tactically-minded players.
If they make all the wrong choices, I'm sure it could be a challenge.

 

[Jaiken]

In my experience, they'd wipe the floor with this encounter... But I have very optimized and tactically-minded players.
If they make all the wrong choices, I'm sure it could be a challenge.

My dice rolls could end up many the challenge a joke. As has been in my experience.

 

[Stormonu]

Ugh? Featureless room? Throw in some elements the players can use or have it used against them. Grells hiding in fog in the air above. A pool of mildly acidic/entangling goo that heals the Mind Flayer. A concealed door the spellcaster can duck through and leave a harmful area of effect behind.

Put the players off-balance as I don't think the monsters themselves will be much of a challenge otherwise.

 

[NotAYakk]

There are some simple tools to estimate how big a fight will be.

The first is simply to add up the HP of the monsters and divide by an estimated DPR of the PCs. This gives you "how many rounds will this take" number.

It doesn't say if the fight will be challenging etc. But a fight that takes 1 or 2 rounds isn't going to be a great one - you want 3 rounds, and maybe 4 or 5 for an epic battle.

The next is to look at the enemy's peak damage flux or DPR. How much damage can they put out in a single round? And compare it to the PC's HP. If this exceeds (or almost approaches) the PC's HP, you are risking a full TPK regardless of anything else. Include modestly optimistic estimates of the ability of AOEs to hit PCs.

A third tool is combat volume. For each monster, do its DPR times its HP times (AC+ATK)/10. Do the same for PCs. (You can use (AC+SaveDC-8)/10 instead if the creature/PC mainly uses saves). Include self-healing as HP. Raise to the 0.7th power then add them up. (half-on-save damage is x4/3, auto-hit x1.5, AOE damage is .5 + targets/2, treat healing of allies as half HP and half damage or assign the healing of allies to allies HP, either way).

So a Paladin who you expect to smite for 4d8 every round and does 30 DPR with weapons and has 20 AC and 92 HP with a +10 to ATK is (3 * 92 * (30+27))^.7 = 866 combat volume. Optimization can ramp this up.

A fighter with 30 HP self heal, 103 HP, 21 AC, 50 DPR at +12 to hit and an action surge (so gets 1/3 of an extra attack round over the first 3 rounds of a fight) is 103 * (3.3) * 67 (^.7) = 1123 combat volume

A naive wizard you expect to AOE for 32 save half on 2.5 targets twice, plus a single target 50 Damage spell, with 15+5 (shield) AC 68 HP and a 20 save DC, is 3.2 * (66) * 68 = 812 combat volume

In anycase, working out your players combat volume isn't all that hard.

On team monster we get:
Champion is 2.5 * 163 * 3*15 (^.7) for 965 combat volume.
Grell 1.6 * 20 (+6 ish from its effects) * 55 for 187 combat volume. (x2)
Mind Flayer: 2.2 * 71 * 1/3 [ 22*2 * 1.5 blasts + 15 tentacles + 0.5 * 50 dominate monster ] (^.7) = 416
Archmage: Use XP hack (see below) for 1957 combat volume (Or napkin math using spells, 2.4 * 150 * 90 (^7) for 1437), depends on how smart you play it.

Total 3712 combat volume.

This volume refers to the fact it is an estimate of damage and durability (product) with accuracy / miss chance estimated. The .7 accounts for the fact that you can chip away and focus fire and aoe groups of monsters. (A 200 HP 50 DPR monster isn't worth 4 100 HP 25 DPR monsters, but closer to 3ish).

If the PCs are all 1000ish, 5k vs 3.7k will be a tough fight where a PC could die if team monster plays brutally.

Volume is just a hack to quickly emulate "they beat on each other, who wins at the end". You can also do that - create a simplified model of each character and monster and simulate the combat.

...

The room is boring. Don't use boring rooms.

The fight lacks motiviation. "Kill everyone on the other side" is not a great motivation. Especially with people on team monster that can teleport and plane shift, why are they fighting the PCs at all? If it is "vermin control" with the mind flayer in charge, then the mind flayer has no reason to stick around if the PCs are challenging, and will instead retreat and raise an alarm.

...

For monsters, a shortcut you can use for combat volume is very roughly (XP*6ish)^.7, at least when I checked it in 2014, but using real values from a monster is probably better. Possibly 2024 uses different monster power levels, I haven't double checked.

(The 0.7 power eliminates the need to do scaling based on number of monsters in 2014 math.)

...

A nice thing about combat volume is that it lets you deal with situational stuff, like "the monsters set off an opening trap". That just ups the triggering monsters DPR in a sense.

 

[Jaiken]

There are some simple tools to estimate how big a fight will be.

The first is simply to add up the HP of the monsters and divide by an estimated DPR of the PCs. This gives you "how many rounds will this take" number.

It doesn't say if the fight will be challenging etc. But a fight that takes 1 or 2 rounds isn't going to be a great one - you want 3 rounds, and maybe 4 or 5 for an epic battle.

The next is to look at the enemy's peak damage flux or DPR. How much damage can they put out in a single round? And compare it to the PC's HP. If this exceeds (or almost approaches) the PC's HP, you are risking a full TPK regardless of anything else. Include modestly optimistic estimates of the ability of AOEs to hit PCs.

A third tool is combat volume. For each monster, do its DPR times its HP times (AC+ATK)/10. Do the same for PCs. (You can use (AC+SaveDC-8)/10 instead if the creature/PC mainly uses saves). Include self-healing as HP. Raise to the 0.7th power then add them up. (half-on-save damage is x4/3, auto-hit x1.5, AOE damage is .5 + targets/2, treat healing of allies as half HP and half damage or assign the healing of allies to allies HP, either way).

So a Paladin who you expect to smite for 4d8 every round and does 30 DPR with weapons and has 20 AC and 92 HP with a +10 to ATK is (3 * 92 * (30+27))^.7 = 866 combat volume. Optimization can ramp this up.

A fighter with 30 HP self heal, 103 HP, 21 AC, 50 DPR at +12 to hit and an action surge (so gets 1/3 of an extra attack round over the first 3 rounds of a fight) is 103 * (3.3) * 67 (^.7) = 1123 combat volume

A naive wizard you expect to AOE for 32 save half on 2.5 targets twice, plus a single target 50 Damage spell, with 15+5 (shield) AC 68 HP and a 20 save DC, is 3.2 * (66) * 68 = 812 combat volume

In anycase, working out your players combat volume isn't all that hard.

On team monster we get:
Champion is 2.5 * 163 * 3*15 (^.7) for 965 combat volume.
Grell 1.6 * 20 (+6 ish from its effects) * 55 for 187 combat volume. (x2)
Mind Flayer: 2.2 * 71 * 1/3 [ 22*2 * 1.5 blasts + 15 tentacles + 0.5 * 50 dominate monster ] (^.7) = 416
Archmage: Use XP hack (see below) for 1957 combat volume (Or napkin math using spells, 2.4 * 150 * 90 (^7) for 1437), depends on how smart you play it.

Total 3712 combat volume.

This volume refers to the fact it is an estimate of damage and durability (product) with accuracy / miss chance estimated. The .7 accounts for the fact that you can chip away and focus fire and aoe groups of monsters. (A 200 HP 50 DPR monster isn't worth 4 100 HP 25 DPR monsters, but closer to 3ish).

If the PCs are all 1000ish, 5k vs 3.7k will be a tough fight where a PC could die if team monster plays brutally.

Volume is just a hack to quickly emulate "they beat on each other, who wins at the end". You can also do that - create a simplified model of each character and monster and simulate the combat.

...

The room is boring. Don't use boring rooms.

The fight lacks motiviation. "Kill everyone on the other side" is not a great motivation. Especially with people on team monster that can teleport and plane shift, why are they fighting the PCs at all? If it is "vermin control" with the mind flayer in charge, then the mind flayer has no reason to stick around if the PCs are challenging, and will instead retreat and raise an alarm.

...

For monsters, a shortcut you can use for combat volume is very roughly (XP*6ish)^.7, at least when I checked it in 2014, but using real values from a monster is probably better. Possibly 2024 uses different monster power levels, I haven't double checked.

(The 0.7 power eliminates the need to do scaling based on number of monsters in 2014 math.)

...

A nice thing about combat volume is that it lets you deal with situational stuff, like "the monsters set off an opening trap". That just ups the triggering monsters DPR in a sense.

Will keep this stuff in mind for the future. Thanks for the calculations.